// Author: combacsa@kaist.ac.kr
// http://www.jungol.co.kr/prog/Hanal/hanalView.php?qs_code=133

//#define COMPILE
#ifdef COMPILE

#include <fstream>
#include <iomanip>
using namespace std;

double round(double x) {
	return (double)((int)(x * 100 + 0.5)) / 100.0;
}


int main() {
	ifstream in("input.txt");
	int n;
	int sum;
	in >> n;
	sum = 0;
	for (int i = 0; i < n; i++) {
		int x;
		in >> x;
		sum += x;
	}
	in.close();
	ofstream out("output.txt");
	out << fixed << setprecision(2) << round((double)(sum) / (double)(n)) << endl;
	out.close();


	return 0;
}
#endif
